高エントロピー合金におけるチューニング要素の分布,構造および性質
Qingqing Ding1, Yin Zhang2, Xiao Chen3
1Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, China.
Nature
|October 11, 2019
まとめ
新しい高エントロピー合金では,制御された元素の結合により,機械的性質が向上する. 原子スケールマッピングは,CrFeCoNiPd合金における組成の変動が強度と柔らかさを改善する方法を明らかにします.
科学分野:
- 材料科学
- 金属工学
- ナノテクノロジー
背景:
- 高エントロピー合金 (HEA) は,複雑な組成によりユニークな機械的性質を備えています.
- 構成-構造-性質の関係を理解することは,HEA設計において極めて重要です.
- 原子スケールでの元素の分布は 物質の振る舞いに大きく影響します
研究 の 目的:
- 面中心の立方体 (FCC) の高エントロピー合金における原子スケールの元素分布を調査する.
- Cantor合金 (CrMnFeCoNi) と新しいFCC合金 (CrFeCoNiPd) を比較する.
- 要素の分布と機械的性質と変形メカニズムを相関させる.
主な方法:
- 原子解像度の化学マッピングで 元素の分布を分析する
- 張力実験中のインサイト伝送電子顕微鏡 (TEM).
- 脱位滑り,横滑り,相互作用の分析
主要な成果:
- 均一なCantor合金と比較して,CrFeCoNiPd合金は重要な要素の集積 (1-3nm波長) を示しています.
- CrFeCoNiPdのナノスケールストレンスフィールドは,変位の滑り方を阻害します.
- CrFeCoNiPdは,大規模な脱位クロススリップと強い脱位相互作用を示しています.
- CrFeCoNiPdは,ストレスの硬化と柔らかさを維持しながら,より高い強度を示しています.
結論:
- CrFeCoNiPdの顕著な組成変動と積み重ねの欠陥エネルギーの増加は,ユニークな変形メカニズムを駆動します.
- 原子スケールの要素マッピングは,優れた機械性能を持つHEAを設計するための洞察を提供します.
- 材料の構成と原子構成を 調整することが 優れた材料特性を 達成する鍵となります
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