Development of high-performance magnetostrictive alloys by gallium diffusion into grain-oriented electrical steel sheets.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04707
• 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: Tohoku University
• Principal Investigator: Kawamata Toru 東北大学, 金属材料研究所, 助教 (90638355)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 磁歪材料 / 電磁鋼板 / 電析めっき / 環境発電

Outline of Final Research Achievements

In this study, Fe-Si-Ga alloys with gallium diffused into commercially available high grade grain-oriented (GO) electrical steel sheets were prepared with the aim of developing inexpensive and high-performance magnetostrictive materials as an alternative to FeGa single-crystal alloys. Gallium was uniformly diffused into the GO electrical steel sheets by electrodeposition plating and annealing. It was found that the addition of Ga to the directional electromagnetic steel sheet causes a decrease in Young's modulus and an increase in magnetostriction with respect to the <100> orientation, which are characteristic of FeGa single-crystal alloys. It is also revealed that the magnetostriction and reverse magnetostriction capability are improved by adding small amounts of additional elements. These results suggest that the Fe-Si-Ga alloy with gallium diffused into the GO electrical steel sheets is a promising low-cost alternative to Fe-Ga single-crystal alloys.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

の回りに発生する機械的振動エネルギーを有用な電気エネルギーに変換する環境発電 (エネルギーハーベスティング)技術として, FeGa単結晶合金を用いた逆磁歪式振動発電デバイスが期待されているが, 実用化・普及に際してFeGa単結晶合金の低コスト化が大きな課題となっている. 本研究では, 長年に渡る研究開発により既に低コスト化・量産化の技術が確立されているFeSi方向性電磁鋼板をテンプレート材料として, これにガリウム元素を浸透させることにより, 結晶方位の集積した安価な ”方向性FeGa合金” を得るための新規合成手法を確立し、その特性を明らかにした。