ナノ結晶銅の強さの最大値である
Jakob Schiøtz1, Karsten W Jacobsen
1Center for Atomic-Scale Materials Physics (CAMP), Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark. schiotz@fysik.dtu.dk
まとめ
銅のプラスチックの変形は,10-15nmの粒径で最大強度を示します. これは,粒子の大きさが減少するにつれて,変位から粒子の境界滑りメカニズムへのシフトが原因です.
科学分野:
- 材料科学 材料科学とは
- コンピューティング・マテリアル・サイエンス・サイエンス
- ナノテクノロジー ナノテクノロジー
背景:
- ナノ結晶材料の機械的性質は,その微細構造特性に大きく依存しています.
- 粒子の大きさと材料の強さの関係を理解することは,高度な材料の設計に不可欠です.
研究 の 目的:
- 大規模シミュレーションを使用して,ナノ結晶銅のプラスチック変形機構を調査する.
- ナノ結晶銅の強度と流動張力に対する粒子の大きさの影響を決定する.
- 観測された粒子の大きさの強化または弱体化効果に起因する基礎的な顕微鏡のメカニズムを解明する.
主な方法:
- 1億個の原子までのシステムサイズの分子動力学シミュレーションを使用しました.
- ナノ結晶銅の試料の粒径を5〜50ナノメートルで変えた.
- 粒子の大きさの関数として変形機構の変化を分析した.
主要な成果:
- 10〜15ナノメートルの粒径で,流動張力と材料強さのピークを特定しました.
- 主要なプラスチックの変形メカニズムでの移行が観察されました.
- 変位媒介の可塑性は,より粗い粒度で一般的であったが,ナノ結晶領域では粒度境界の滑り方が支配的であった.
結論:
- ナノ結晶銅の強度は,特定の粒子のサイズ範囲 (10〜15 nm) で最大を示します.
- この最大強度は,変形メカニズムにおける根本的なシフトに起因する.
- シミュレーション結果は,多結晶金属の機械的性質の粒子の大きさの依存性についての洞察を提供します.
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