磁場による形状回復は,逆相変換による形状回復である
1Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579, Japan. kainuma@material.tohoku.ac.jp
Nature
|February 24, 2006
まとめ
この研究では,NiCoMnIn合金で,磁場による形状回復が顕著であり,100MPa以上のストレスを発生していることが報告されています. このヒュースラー合金には,高度な磁気アクチュエータのアプリケーションの可能性があることが示されています.
科学分野:
- マテリアルサイエンス 材料科学
- 凝縮物質物理学 凝縮物質物理学
- マグネティズム (磁気) とは
背景:
- ボディを中心とした立方体の構造を持つハウスラー合金には,磁場誘発の大きな張りが表れます.
- これらのストレンは,外部磁場の下でのマルテンサイト構造変数の再配置に起因する.
- このような材料は,磁気アクチュエータのアプリケーションの有望な候補です.
研究 の 目的:
- 圧縮的に変形したNiCoMnIn合金における磁場誘発形状回復を調査する.
- この合金のストレス発生と変形回復能力を定量化するために.
- 観察された行動に起因する根本的な変換メカニズムを解明する.
主な方法:
- Ni45Co5Mn36.7In13.3単結晶の実験調査について.
- 先行変形したサンプルに形状回復を誘導するために70 kOeの磁場を適用する.
- 生成されたストレスと観察された変形回復率の測定.
主要な成果:
- NiCoMnIn合金は,70 kOeの磁場を適用すると,100 MPaを超えるストレスを発生しました.
- 3%の変形が観察され,元の形状がほぼ完全に回復しました.
- 生成されるストレスレベルは,以前の鉄磁気形状記憶合金で報告されたレベルの約50倍です.
結論:
- 観測された磁場による形状回復と高ストレスの生成は,逆変換によるものである.
- この変換は,反鉄磁性 (またはパラ磁性) マルテンシート相から298 Kの鉄磁性親相に起こります.
- NiCoMnIn合金は,高性能の磁気アクチュエータ材料として例外的な可能性を示しています.
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