Design of high-entropy casting alloys via elucidation of diverse solidification processes caused by the large degree of freedom

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14522
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26060:Metals production and resources production-related
• Research Institution: Nagoya University (2023); Kyoto University (2022)
• Principal Investigator: Ryoji Katsube 名古屋大学, 工学研究科, 講師 (10839947)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: ハイエントロピー合金 / 鋳造材料 / その場観察 / 能動学習 / 状態図

Outline of Final Research Achievements

High entropy alloys (HEAs), which are multinary alloys with near-equiatomic compositions, have attracted much attention as a metallic material system based on a novel design concept. One of the primary challenges in the design of HEAs is the difficulty in interpreting the microstructure development process through the analysis on the microstructure and the subsequent plotting the results on the phase diagram. The primary objective of this study is to develop HEAs with desirable properties from the view point of solidification with the aid of in-situ observation at the synchrotron facilities and regression methods in the field of machine learning. As a result, we found a Cr-Mn-Fe-Co-Ni alloy with a congruent composition and a Cr-Mn-Fe-Co alloy with low microsegregation and fine microstructure derived from the BCC-FCC phase transformation.

Free Research Field

金属・資源生産工学

Academic Significance and Societal Importance of the Research Achievements

文明の発展とともに，社会を支える材料に求められる機能や特性は高度化・複雑化しており，それに答えるために多元素化が進んでいる．多元材料の組成空間はもはや人間の知覚の範疇を超えているため，機械学習分野の知見を利用によってHEAの全組成域から材料探索した本研究は，今後の金属材料研究のマイルストーンとして学術的意義がある．さらに，本研究の成果として典型的なHEA系であるCr-Mn-Fe-Co-Ni系の一致溶融組成や固相変態を利用した微細組織・ミクロ偏析フリー合金を見出しており，これらの機械特性に有用性が認められれば社会的波及効果も見込める．