ナノ粒子の金属の熱安定性を高め,臨界粒子のサイズを下回る

X Zhou^1,2, X Y Li³, K Lu³

¹Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.

Science (New York, N.Y.)

|May 5, 2018

まとめ

銅やニッケルのようなナノ粒子の金属は驚くべき熱安定性を示しています小粒の大きさは安定性を高め,高温下でも,独特の粒子の境界進化により,粗化を防止します.

科学分野:

材料科学
金属工学
ナノテクノロジー

背景:

ナノ粒子の材料は,高温で粒子が粗くなるため,限界に直面しています.
ナノスケール材料の粒子の粗化は,環境温度でさえ,かなり低い温度で起こります.
この不安定さはナノ構造の金属の実践的な応用を制限しています

研究の目的:

純粋な銅とニッケルでナノメートルの粒子の熱安定性を調べる
ナノ構造の金属の粒径と熱安定性の関係を理解する.
ナノグラインの熱安定性を高める根本的なメカニズムを探求する.

主な方法:

銅とニッケルでナノメートルの大きさの粒子を低温のプラスチック変形で生成する.
様々な温度で製造されたナノ粒子の材料の熱安定性試験.
先進的な顕微鏡と特徴付け技術を用いた穀物境界の進化と欠陥構造の分析.

主要な成果:

純粋な銅とニッケルでナノメートルの大きさの粒子は,重要な粒子の大きさ以下では,著しい熱安定性を示す.
不安定が生じる気温は,粒子のサイズが小さくなると大きく上昇します.
ナノ粒子は従来の粗粒子の材料の再結晶温度を超えても安定していた.

結論:

ナノ粒子の固有の熱安定性は,低エネルギー状態への自律的な粒子の境界進化と関連しています.
この安定化メカニズムにおいて,プラスチックの変形中の部分的変位の活性化が重要な役割を果たします.
この発見により,より堅固なナノ構造の材料を高温アプリケーションに開発する道が開けています

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